als47

Please note that the 2007 RX350 does not have a timing belt, but rather a timing chain, which is not often replaced. The rest, I fully agree. A bad water pump would also start leaking, giving some indication of going bad.

I have the same car, bought in 2009, with 18,000 miles on it. Currently it is close to 100,000 miles. It still has that light tapping noise when cold, but it does go away when warmed up. I asked the dealer a while back and the response was that it is not the valves but rather the fuel injectors. Not so sure about that, but it has not become worse over these many years and miles. The oil, whether conventional or synthetic, does not seem to make any difference at all. I have been using conventional 5W-30 all along, changed at 5K intervals, and the engine is perfect, with the oil surprising clean at the end of the interval. Now regarding the gasoline octane. The car REQUIRES minimum 91 grade. When I bought it, the dealer said I could use 87. Well, under light load, it worked OK, but the moment I hit a hill, or accelerated hard, the engine pinged like crazy and the entire front end shook wildly. Checking the manual afterwards, it said very clearly not to use any gas under 91, unless in an emergency! Most likely, the previous owner drove the car very lightly so she may have not noted the poor behavior during more realistic driving, but at the same time, it is very unlikely she permanently damaged it. So just use 91 or 93 octane and you will enjoy the car for a long time.

Just a note to some remarks above: the RX 350 does not have a timing belt, but rather a timing chain. It does have obviously an accessory (serpentine) belt. You check this one periodically for wear, glazing, etc.

Very unlikely for all coils to go bad at the same time. Have it rechecked. I replaced twice a coil, luckily both times they were in the front bank of cylinders. Never had a problem since, about 3 or 4 years.

Over the last few years, I have replaced a couple of ignition coils in my 2007 RX350 and there was never a need to reset the OBD. All the warning/diagnostic lights reverted to normal after a few miles of driving.

I agree with the previous comments. Get the codes. The front ignition coils (cylinders 02, 04, 06) are very easy to get to. The rear ones (01, 03, 05) are unfortunately a pain! Maybe you're lucky. I have the same model, with about 80K miles in it, I have had to replace 2 front ignition coils, but not at the same time; they are about $110-120 a piece. As to the spark plugs, I have not had any problem so far on my car, and I doubt that all of them would go bad at the same time.

I agree with the other responder. If you do not notice any leakage, you should be all right. Anti-freeze leakage (and the associated drop in coolant level) is the sure sign of the need to replace it. I also have about 85K in my RX 350 and the cooling system is fine.

The RX 350s do not have a timing belt (they have a timing chain instead). Yes, the drive belt is the long serpentine belt. At 86K, it is not inconceivable to show some wear, may want to have a second opinion if you have a mechanic you can trust.

FYI, The plural of Lexus is Lexi. Sounding the i as a long i. Your Latin grammar admonition would be correct if Lexus were an actual singular Latin word. It is not, it is an invented word, and the rules of the plural on it are much looser. That said, any opportunity to review my high school Latin is much appreciated.

And exactly how is all this Lexus-related? Can we keep this forum focused on what's supposed to be? There are other ways and avenues to vent your feelings. But just to clear the air: all these tax -exempt "social welfare" (???) organizations, crying of oppression and discrimination, are all BS, deep and unadulterated. Money, unlimited money, in our political system, are destroying the country. So now, back to our Lexuses...

Hi Liam, Simply push in the AUTO once; it puts it in MANUAL mode; the same effect may be achieved by going into CLIMATE display and choosing some ventilation mode other than the AUTO currently has the system in; it switches off the AUTO mode as well. Anyway, perhaps this would tell us if the AUTO mode is the issue or it's something common to both. Also you might try to turn the temp setting all the way up, I think it's 85, to see if you get some heat.

I got the same answer from the dealership's tech. I guess we have to live with it. I have seen many complaints about this, but apparently it is innocuous.

Have you tried the "Manual" mode?